UI Scroll Performance & Rendering Fixes

Date: 2026-02-10 Status: Implemented Author: Sri Aradhyula <sraradhy@cisco.com>

Motivation

The CAIPE UI was experiencing performance issues in three areas:

1. Thinking messages: Auto-scroll forced users to the bottom on every 100ms content update, causing layout thrashing and preventing users from reading earlier content.
2. A2A Debug panel: Broken scroll (ref pointed to non-scrollable element), all events rendered without virtualization, and excessive re-renders from broad Zustand store subscriptions.
3. History rendering: No React.memo on any component, causing the entire message list to re-render on every streaming update. ReactMarkdown ran on every token chunk during streaming.

Related

• Architecture: architecture.md